1. Field of the Invention
This invention relates to an endoscope wherein an insertable part is covered with a tubular outer cover.
2. Related Art Statement
In recent years, medical endoscopes are extensively used to observe organs within a body cavity by inserting an elongated insertable part into the body cavity or to make various curing treatments by using forceps inserted through a forceps channel as required. In the industrial field, industrial endoscopes are also extensively used to observe or inspect the interior of boilers, turbines, engines, chemical plants or the like.
A rigid tip part is provided on the tip side of the insertable part of the endoscope, and a curvable part is provided on the rear side adjacent to this tip part. The curvable part can be curved vertically and horizontally by rotating a curving operation knob provided on an operating part.
Among the industrial endoscopes, there is one in which 3 the insertable part is protected by an outer protective sheath constituted by a net tube (blades) obtained by knitting fine wires of a metal or the like into the form of a net. In addition, there is another industrial endoscope in which the strength of the tightness of the outer protective sheath is varied between the curvable part and a flexible part disposed rearwardly of the curvable part because the degree of curvature varies between the curvable part and the flexible part. When the strength of the tightness of the outer protective sheath is thus to be varied, the outer protective sheath in the vicinity of a boundary between the curvable part and the flexible part is secured to an inner flexible pipe protected by the outer protective sheath, by means of a cylindrical fixing member externally fitted onto the outer protective sheath.
However, since the cylindrical fixing member projects radially outwardly of the outer periphery of the outer protective sheath, there is a problem in that particularly when the insertable part is removed from an object into which the insertable part is inserted, an end portion of the fixing member may be caught inside the object into which the insertable part is inserted.